Plane/pleɪn/ Definition 1 of 6Pro Tip 1/3Transportation Context Refers to flying vehicles, often used when discussing travel. We took a plane to Paris for our vacation. Pro Tip 2/3Air Travel Common 'Plane' is commonly used; aircraft or airplane are more formal or technical. Check in 2 hours before the plane departs. Pro Tip 3/3Visualizing Scale Helps understand size; planes are large and carry many people. A plane can be as big as a building.